Field
Exemplary embodiments relate to a semiconductor inspection device and a method of inspecting a semiconductor pattern using the same, and, more particularly, to a semiconductor inspection device configured to measure a profile of a semiconductor pattern and a method of measuring a profile of a semiconductor pattern using the same.
Discussion
High performance semiconductors are used in various electronic devices. An aspect of designing a high performance semiconductor device may include scaling down the size of a semiconductor device so that more semiconductor devices may be formed on a single wafer (or substrate). As a way of increasing a degree of integration of a semiconductor device, a vertically structured semiconductor device, such as V-NAND, may be utilized to reduce the size (or footprint) of the semiconductor device, while increasing the number of formed cells.
Fabricating highly integrated semiconductor devices, such as vertically structured semiconductor devices, may involve forming various patterns in a semiconductor device, such as holes, to electrically and/or physically connect elements patterned across multiple layers. For example, symmetrically formed holes may be formed in a semiconductor structure to generally improve the electrical characteristics of a semiconductor device. However, during the semiconductor fabrication process, semiconductor patterns, such as holes, may be formed asymmetrically. As such, the patterns may be misaligned with other components or a planar surface of a substrate. This may degrade electrical characteristics of the semiconductor device.
Non-destructive inspection devices may be used to identify a semiconductor pattern having asymmetrical orientation. Non-destructive inspection devices may include a spectroscopic ellipsometer. A spectroscopic ellipsometer may measure optical properties of a target by emitting a polarized beam towards the target and detecting scattered or reflected signals from the target. In this manner, the spectroscopic ellipsometer may collect the detected signals and calculate a 4×4 matrix (or Mueller matrix) to generate an optical profile (e.g., polarimetric properties) of the target. Generally, in semiconductor fabrication, the target may include a semiconductor device and the optical profile may include asymmetry of a semiconductor pattern in the semiconductor device.
Mueller matrix components, such as (1,3), (1,4), (2,3), and (2,4) components, may be used to identify asymmetry in the target. For instance, a spectroscopic ellipsometer utilizing a Mueller matrix may measure an asymmetry of the target by predetermining an inclined direction of a semiconductor pattern formed therein. The predetermined inclined direction may be a presumed value because the inclined direction of a semiconductor pattern, such as a hole, may not be externally observable. When the predetermined direction of the semiconductor pattern does not correspond to an actual inclined direction of the semiconductor pattern, depending on an azimuthal angle of the polarized beam incident to the target, the Muller matrix components representing the asymmetry may be zero (0). This may indicate a symmetrical orientation even though the holes may be inclined. Given that the output of a conventional spectroscopic ellipsometer may rely on the presumed orientation of the semiconductor pattern, it is difficult to generate a correct profile of a semiconductor pattern.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.